Steps to reproduce:
1. Download the project attached by the user
2. Build "test" scene to iOS
3. Build the project to an iOS device

Result: Crash when calling JoinMulticastGroup function in UDPResponder.cs:114 (full stack trace in notes)
* frame #0: 0x0000000100b1e9a0 ISOTest`il2cpp::vm::Field::GetValueObject(field=0x0000000000000000, obj=0x00000001071ed930) at Field.cpp:66 [opt]
frame #1: 0x0000000100aff3e8 ISOTest`il2cpp::icalls::System::System::Net::Sockets::Socket::SetSocketOption(socket=<unavailable>, level=kSocketOptionLevelIP, name=kSocketOptionNameAddMembership, obj_val=0x00000001071ed930, byte_val=<unavailable>, int_val=<unavailable>, error=0x000000016fded0fc) at Socket.cpp:1253 [opt]
frame #2: 0x00000001002e8b64 ISOTest`::Socket_SetSocketOption_internal_m2172448896(RuntimeObject *, SafeSocketHandle_t3383195703 *, int32_t, int32_t, RuntimeObject *, ByteU5BU5D_t1923580303 *, int32_t, int32_t *, const RuntimeMethod *) [inlined] Socket_SetSocketOption_internal_m1553434245(___level1=<unavailable>, ___name2=<unavailable>, ___obj_val3=<unavailable>, ___byte_val4=<unavailable>, ___int_val5=<unavailable>, ___error6=<unavailable>) at Bulk_System_4.cpp:32813 [opt]

Expected result: Calling JoinMulticastGroup does
Reproduced on: 2017.1.0p5, 2017.2.0b9
Did not reproduce: 2017.3.0a4